The ground fault circuit interrupter (GFCI) is a leakage protection product widely used in countries/regions such as the United States, Canada, North America, and South America. It plays an important role in protecting safety of lives and property of the people in the aforementioned areas. An existing GFCI generally comprises a base, a cover with receptacle jacks, an electromagnetic tripping mechanism, a contact assembly, a grounding assembly, a power input connection assembly, a power output connection assembly, and other components. Its circuits include a power supply circuit, a leakage grounding detection circuit, a signal amplifying circuit, a power supply indicator circuit, a manual detection circuit, a reverse connection detection and execution circuit, and a tripping mechanism driving circuit. The electromagnetic tripping mechanism is controlled by the leakage grounding detection circuit. The GFCI can supply power to the load through the receptacle jacks in the cover, and can also provide power to the load connected thereof through the power output connection assembly. US patent application publications with the numbers US2013021120A1 and US2013038968A1 disclose the above conventional GFCI.
Due to existing restrictions on circuit design, the conventional GFCI suffers the following security risks: if the power lines are reversely connected due to the mistake of the installer during installation and use of a GFCI, the GFCI fails to function for leakage protection in the reset state and imposes a safety risk arising from the reverse connection because it is difficult to notice the reverse connection when the power is off.